Merge pull request #8492 from statsmodels/pins

MAINT: Refine pins

Merge pull request #8493 from statsmodels/final-docs

DOC: Final 0.13.3 docs

Merge pull request #8107 from bashtage/release-note

MAINT: Release note for 0.13.2

Merge pull request #7881 from statsmodels/release-note-0-13-1

RLS: Release 0.13.1 documentation

Merge pull request #7775 from bashtage/0.14-dev

MAINT: Start 0.14 development

Merge pull request #7774 from bashtage/rls-0.13-doc

DOC: Final update to change log

Merge pull request #7727 from josef-pkt/docs_recent

DOC: improve docs and docstrings, mainly for recent additions

Merge pull request #7303 from ChadFulton/rls-note

DOC: Minor updates to v0.12.2 release notes

Merge pull request #7123 from bashtage/port-7118

DOC: Port missed doc fix

Tag for 0.13 development